MySQL EXPLAIN is a tool that helps to optimize SQL queries by providing information about how MySQL executes the query. It returns a description of the execution plan that MySQL uses for the SELECT statement and provides details on how indexes are used, how tables are joined, and other important metrics that can help improve query performance.
The output of the EXPLAIN command shows:
- The order in which tables are accessed
- Which indexes are used
- How data is filtered or sorted
- If temporary tables are created during query execution
Using this information, developers can identify performance bottlenecks in their queries and adjust them accordingly. They can also use EXPLAIN to determine if they need to create new indexes or modify existing ones.
Overall, MySQL EXPLAIN is an essential tool for optimizing database performance by identifying slow queries and improving their execution time.
